Effect of the different printing patterns of graphene nanoparticles in conductive ink on electrical and mechanical performance

The utilization of graphene in the formation of conductive ink has been positively accepted by the electronics industry especially with the emerging of printable and flexible electronics. Because of that, it motivates this study to investigate the electrical, mechanical, and morphological properties for different patterns of Graphene Nanoparticle (GNP) conductive ink. The samples were prepared using the screen-printing technique with a low annealing temperature of 100 ºC for 30 minutes. The investigated parameter for the electrical property was the sheet resistivity, which showed that the zigzag pattern recorded the highest value of 1.077 kΩ/sq at the 3 mm of ink thickness. For the mechanical properties, the highest of hardness for 2 mm thickness was the curve pattern and for 3 mm was the square pattern, with the values of 3.849 GPa and 4.913 GPa. Both maximum values showed a direct correlation with the behavior of the elastic modulus of the ink. The maximum values of elastic modulus were recorded at the same ink pattern and thickness. For the morphological analysis, the surface roughness and qualitative analysis using SEM images were performed. The surface roughness showed that the increase of GNP in the composition increased the surface roughness because it decreased the homogeneity of the mixture. The recorded SEM images of the ink layer microstructure surface showed a direct correlation with the obtained sheet resistivity data. The samples that produced high sheet resistivity showed the presence of bumps, creases, and defects on the ink layer surface. Based on the obtained data, the correlation between electrical, mechanical, and morphological properties can be established for the GNP conductive ink with various patterns and thicknesses

The Effect Of Curing Time On Electrical Resistivity, Mechanical Characteristics And Microstructure Behavior Of Graphene Conductive Ink

Nowadays graphene conductive ink (CI) are expected to be widely used for various automotive safety electronic equipment in the future. Graphene has a potential advantage such as high electrical conductivity and thermal conductivity and can be applied to electronic circuits in vehicles especially for driver health monitoring systems. To ensure optimal conductivity, graphene need to go through a curing process to minimize porosity between particles and create a smooth conductive track. The effect of curing time on electrical, mechanical, and microstructural properties was investigated. Five samples at 20 wt.% filler loading with curing times varying from 10-50 minutes with each sample interval of 10 minutes was executed using doctor-blading printing method before analysis. Then, the analysis is done by using four-point probe to measure resistance, followed by nanoindentation and scanning electron microscope (SEM) to study elasticity and observe microstructure behaviour respectively with respect to temperature. Sample of 30 minutes curing time gives the lowest result, 24.9046 Ω.cm for volume of resistivity. The sample also has excellent mechanical properties, with high Young's modulus and low hardness, 8.59 GPa and 7.59 MPa respectively. Stretchable conductive ink (SCI) in vehicle electronic equipment with low resistance and high elasticity can monitor the driver's health more refectively because it can be stretched to fit the shape of the human body. It also has good conductivity for measuring human pulse and muscle movement